A semiconductor device may include a plurality of semiconductor devices formed on a single substrate. For example, a semiconductor wafer may include a plurality of dies that may be processed to form a plurality of dies from a single semiconductor wafer. Various processes may be used to separate the semiconductor device into a plurality of semiconductor devices.
Stealth dicing through tape is one process that may be used to separate the semiconductor wafer into a plurality of semiconductor devices. The semiconductor device typically may comprise a circuitry layer positioned on a silicon layer. The circuitry layer comprising the top surface and the silicon layer comprising the bottom surface. The back side or bottom surface of the semiconductor wafer is applied to a tape material. Various tape materials may be used such as Lintec D-L01wtest38 tape.
A laser tool is then used to irradiate an infrared laser through the tape on the back side of the wafer. A focal point of the infrared laser is positioned substantially with a middle portion of the silicon layer of the semiconductor wafer. The infrared laser cleaves a portion of the silicon lattice of the silicon layer. The infrared laser is irradiated in a pattern along the back side of the semiconductor wafer. The pattern is typically a grid pattern that divides the semiconductor wafer into individual dies. The infrared laser does not penetrate the circuitry layer of the semiconductor wafer and the semiconductor wafer is still intact after the lasing processes with portions of the silicon lattice being cleaved in a pattern along the interfaces between the individual dies. A tape expander machine is then used to apply an expanding force to the tape attached to the back of the semiconductor wafer. The expansion of the tape causes the silicon lattice to break apart where it has been cleaved by the infrared laser. The separation of the silicon layer also causes the circuitry layer to break apart along the same pattern to separate the semiconductor wafer into a plurality of individual dies.
The stealth dicing through tape process works well to separate a semiconductor wafer into individual dies when a thickness of the silicon layer is much larger than a thickness of the circuitry layer. For example, the silicon layer may be 55 microns thick and the circuitry layer may be 6 microns thick. However, as the ratio of the thickness of the silicon layer to the circuitry layer decreases the circuitry layer may not be cleanly separated by the expansion of the tape material. For example, the stealth dicing through tape process does not cleanly separate the metal layer into individual dies with the thickness of the silicon layer is 22 microns and the thickness of the circuitry layer is 6 microns.
Additional drawbacks and disadvantages may exist.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the disclosure as defined by the appended claims.